JPH11296874A - Recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time until the reproduction of sound while making use of the advantage of the automatic adjustment of a servo constant by compar ing identification information characteristic to a recording medium to reproduce and stored identification information in a recording medium with each other at the time of reproducing the recording medium and properly controlling servo characteristic at the time of coincidence. SOLUTION: A servo constant is stored in a storing part 12 before mounting an optical disk for reproduction. At the time of mounting the optical disk 1, focusing servo and tracking servo are given by this stored data to read TOC information recorded in the optical disk and from disk characteristic information for identifying the optical disk 1, a control part 8 discriminates that the disk 1 is the servo adjusting reference CD registered to the part 12. When this is the first mounting after supplying a power source, servo automatic adjusting operation is started to obtain gain and phase compensation data and this data is updated as data of reference DC of the part 12 to finish automatic adjustment to start recording track reproduction. Thus, servo is given speedily to read a record in the optical disk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus for a recording medium for recording or reproducing data such as an audio signal.

[0002]

2. Description of the Related Art The prior art will be described with reference to a case where a compact disk (hereinafter referred to as a CD) is used as a recording medium.

FIG. 2 is an overall configuration diagram showing the configuration of a conventional optical disk reproducing apparatus. The optical disk 1 is mounted on a turntable fixed to a spindle motor 2 and rotates at a predetermined linear speed. The optical pickup 3 focuses light emitted by a laser diode incorporated in the optical pickup by an optical component such as a lens, focuses (hereinafter, focuses) on an information recording unit of the optical disk, and follows the recording track of the optical disk. It is possible to continuously read recorded information from a rotating optical disk.

[0004] The state in which the focus is properly performed is a state in which the spot diameter of the laser beam applied to the information recording portion of the optical disk is optically minimum. Therefore, it suffices to detect the reflected light of the laser light applied to the optical disc and control the spot diameter to be minimum,
For this purpose, a focus error signal can be obtained by calculating the intensity of the reflected light received by each of the four-segment detectors composed of photodiodes that receive the reflected light.

However, since the calculated and output focus error signal has an offset due to a shift in the mounting position of the 4-split detector and a difference in the electric light receiving sensitivity, the bias voltage for correcting the offset is controlled. Must be added to the circuit. A criterion for applying an appropriate bias voltage is to minimize jitter, which is a temporal variation of a waveform of a recording signal read from an optical disk by an optical pickup. Further, an appropriate bias voltage differs for each optical pickup.

The reflected light of the laser beam applied to the information recording section of the optical disk is detected by a four-divided detector in the optical pickup via the optical system of the optical pickup, and the output is amplified by the head amplifier section 5. It is output as a focus error signal and an EFM (Eight to Forteen Moduration) signal. The focus error signal is sent to the servo unit 7, and the EFM signal, which is a reproduction signal of the recording signal, is sent to the signal processing unit 10. The focus error signal sent to the servo unit 7 is amplified and phase-compensated, and the drive unit 6 controls the focus drive coil 4 of the optical pickup.
Drive a.

In order to continuously read information from an optical disk, it is necessary to perform a focus servo for maintaining a stable focus. In other words, it is required that the information surface of the optical disk be stably followed by the fluctuation due to the fluctuation of the information surface, and the phase margin of the control system in which the mechanical system, the optical system, the electric system, etc. of the optical pickup is a loop. In addition, it is necessary to secure a sufficient gain margin.

In order to continuously read information from a rotating optical disk, it is necessary to perform a tracking servo that continuously follows a recording track of the optical disk. The tracking servo is controlled so that the laser diode emitted from the optical pickup 3 detects the edges of both ends of the pit recorded on the information surface of the optical disk and the laser spot is located at the center of the pit which is the recording data of the recording track. .

The optical pickup detects a tracking error signal from the optical disk 1, and the detected tracking error signal is amplified and phase-compensated by a servo section 7, and a driving section 6 drives a tracking coil 4 b of the optical pickup. In order to follow the recording track stably even when vibration is applied from the outside, the phase margin and gain of the control system of the loop system such as the optical pickup mechanical system, optical system, electric system etc. It is necessary to secure enough room.

However, depending on the optical disc to be reproduced, the output of the focus error signal and the tracking error signal depends on the recording state of the recording information section such as the reflectivity of the reflection film on the recording information surface or the height of the pit recorded on the recording track. Are different in size. Therefore, the transfer function of the control system of the focus servo and the tracking servo changes for each optical disk to be reproduced, and the control system becomes appropriate when the gain of the electric circuit portion of the control system and the time constant of the phase compensation circuit are predetermined constant values. Not always, the phase margin and the gain margin of the control system change, and the stability condition of the control system becomes inappropriate. Therefore, by automatically adjusting the phase and the gain of the control system of the focus servo and the tracking servo for each optical disk to be reproduced according to the optical disk, it is possible to secure the optimal phase margin and the gain margin. It is effective if you look at it.

The characteristics of electronic components such as a laser diode and a four-segment detector of an optical pickup are liable to change over time, and also to environmental conditions such as temperature. Therefore, as described above, the phase and gain of the control system can be automatically adjusted according to the optical disk, which is effective from the viewpoint of servo stability.

FIG. 4 is a flowchart showing the operation of the conventional servo automatic adjustment. When the optical disc is loaded into the reproducing apparatus in step S1, the control unit 8 issues a command to start automatic adjustment to the servo unit 7 in step S2. Next, in step S3, the servo unit 7 instructs the drive unit 6 to rotate the spindle motor 2, and performs servo of focus and tracking of the optical pickup 3 with a preset servo constant of an electric circuit.

In step S4, an operation of automatically determining the gain and the amount of phase compensation so as to obtain predetermined servo characteristics is automatically performed. After the servo is activated in step S3, the disturbance voltage (V) output from the disturbance generation circuit of the servo unit
i) is applied to the drive coil to intentionally displace the head portion of the optical pickup, and the magnitude and phase of the voltage (Vo) of the error signal fed back by the focus or tracking error signal are detected. Error signal voltage (V
o) and the ratio of the disturbance voltage (Vi) signal (Vo / Vi) or (Vo / Vi-
By calculating the magnitude and phase of Vo), it is possible to obtain the characteristics of the servo system when reproducing the loaded optical disk. Using the result, the gain and phase compensation of the electric circuit are changed to change the servo constant so that the servo system has proper characteristics.

In step S5, since the gain and phase compensation amounts calculated by the servo section are obtained as digital data, the control section temporarily stores the gain and phase compensation data in a memory and automatically controls the servo system. The adjustment ends.

In step S6 after completion of the automatic adjustment,
Since the recording signal recorded on the optical disk can be read normally, TOC data is read as in the related art.
Thereafter, the operation for reading the audio data is performed.

In step S7, at which reproduction is started, the EFM signal read from the recording track of the optical disk is input to the signal processing unit 10 and demodulated into audio signal data.
C) Input to 11. The DAC is a circuit that converts a digital signal into an analog signal, and is output outside the playback device.

As a prior art, Japanese Patent Application Laid-Open No. 9-448
Japanese Patent Publication No. 64 (automatic adjustment method of focus servo) discloses an optical disc reproducing apparatus for automatically setting a focus servo constant. Further, the above publication describes that data obtained by automatically adjusting the focus servo is stored in a memory, and the data stored in the memory is read out every time the power is turned on to perform a focus servo operation.

[0018]

However, in the prior art for automatically setting the servo constants described above, the servo constant is determined every time the optical disk is loaded into the recording / reproducing apparatus. It is performed every time the recording / reproducing apparatus is loaded, and it takes a long time to output the sound. As a result, audio cannot be output immediately after loading the optical disc,
There is a problem in using it for a broadcast reproducing apparatus that broadcasts while accurately managing time.

Further, according to the method described in JP-A-9-44864, in which data stored in a memory is read out of a servo constant from the memory every time the power is turned on and focus servo is performed, the above-mentioned problem is solved. Since there is no operation to determine the servo constants, the time until audio output can be shortened, but changes in the servo constants due to environmental changes such as temperature changes due to aging of the laser diode or quadrant detector in the optical pickup, etc. It cannot be corrected.

It is an object of the present invention to provide an optical disk recording / reproducing apparatus which utilizes the advantages of automatic adjustment of servo constants and solves the above-mentioned problems.

[0021]

SUMMARY OF THE INVENTION According to the present invention, there is provided a recording / reproducing apparatus for controlling a recording / reproducing unit to write or reproduce recording information on or from a recording medium. Means for reading from the recording medium, control means for controlling the servo characteristics of the servo system of the recording / reproducing section to be appropriate, information unique to the recording medium, the optical characteristics of the recording medium and the recording / reproducing. Storage means for storing servo characteristic data in which the servo characteristics of the unit are set as a single-turn servo system, and operating means for instructing the storage means to store unique information for identifying the recording medium in the recording medium. When reproducing, the control means:
This is a recording / reproducing apparatus that compares unique information for identifying a recording medium to be reproduced with information for identifying a recording medium stored in the storage unit, and when the information matches, controls so that servo characteristics are appropriate. .

Further, according to the present invention, in the above recording / reproducing apparatus, the control means discriminates, when reproducing the recording medium, unique information for identifying the recording medium to be reproduced and the recording medium stored in the storage means. A recording / reproducing apparatus that compares information with information and, when the information matches, stores data of the servo characteristic obtained by controlling the servo characteristic to be appropriate in the storage unit.

According to the present invention, in the above-mentioned recording / reproducing apparatus, the control means, when reproducing the recording medium, identifies the unique information for identifying the recording medium to be reproduced and the recording medium stored in the storage means. A recording / reproducing apparatus which compares information with information and, when the information does not match, uses data of servo characteristics which have been continuously used.

According to the present invention, in the above recording / reproducing apparatus, the control means, when reproducing the recording medium, information specific to the recording medium to be reproduced and information for discriminating the recording medium stored in the storage means. And when the information matches, the operation of controlling the servo characteristics to be appropriate is performed only once after the power of the recording / reproducing device is turned on.

According to the present invention, in the above recording / reproducing apparatus, the control means, when reproducing the recording medium, information specific to the recording medium to be reproduced and information for discriminating the recording medium stored in the storage means. When the information is matched, and when the reproducing operation is performed two or more times after the power of the recording / reproducing apparatus is turned on, the recording / reproducing using the continuously used servo characteristic data is performed. Device.

[0026]

FIG. 1 is an overall configuration diagram showing the configuration of an optical disk recording / reproducing apparatus according to one embodiment of the present invention.
FIG. 1 shows a configuration in which a storage unit 12 for storing information for recognizing individual optical disks is added to the configuration of FIG.

An embodiment of the present invention will be described below with reference to FIG. The optical disk 1 is mounted on a turntable fixed to a spindle motor 2 and rotates at a predetermined linear speed. The optical pickup 3 focuses light emitted by a laser diode incorporated in the optical pickup with an optical component such as a lens, focuses the information on an information recording portion of the optical disk (hereinafter, focus), and follows a recording track of the optical disk. It is possible to continuously read recorded information from a rotating optical disk.

The state where the focus is properly performed is a state where the spot diameter of the laser irradiated on the information recording portion of the optical disk is optically minimum. Therefore, it suffices to detect the reflected light of the laser light applied to the optical disc and control the spot diameter to be minimum,
For this purpose, a focus error signal can be obtained by calculating the intensity of the reflected light received by each of the four-segment detectors composed of photodiodes that receive the reflected light.

However, since the calculated and output focus error signal has an offset due to a shift in the mounting position of the four-segmented detector and a difference in electrical light receiving sensitivity, the bias voltage for correcting the offset is controlled. Must be added to the circuit. A criterion for applying an appropriate bias voltage is to minimize jitter, which is a temporal variation of a waveform of a recording signal read from an optical disk by an optical pickup. Further, an appropriate bias voltage differs for each optical pickup.

The reflected light of the laser beam applied to the information recording section of the optical disk is detected by a four-divided detector in the optical pickup via the optical system of the optical pickup, and the output is amplified by the head amplifier section 5. It is output as a focus error signal and an EFM (Eight to Fourteen Moduration) signal. The focus error signal is sent to the servo unit 7, and the EFM signal, which is a reproduction signal of the recording signal, is sent to the signal processing unit 10. The focus error signal sent to the servo unit 7 is amplified and phase-compensated, and the drive unit 6 controls the focus drive coil 4 of the optical pickup.
Drive a.

In order to continuously read information from the optical disk, it is necessary to perform a focus servo for maintaining a stable focus. In other words, it is required that the information surface of the optical disk be stably followed by the fluctuation due to the fluctuation of the information surface, and the phase margin of the control system in which the mechanical system, the optical system, the electric system, etc. of the optical pickup is a loop. In addition, it is necessary to secure a sufficient gain margin.

In order to continuously read information from a rotating optical disk, it is necessary to perform a tracking servo that continuously follows a recording track of the optical disk. The tracking servo is controlled so that the laser diode emitted from the optical pickup 3 detects the edges of both ends of the pit recorded on the information surface of the optical disk and the laser spot is located at the center of the pit which is the recording data of the recording track. .

The optical pickup detects a tracking error signal from the optical disk 1, and the detected tracking error signal is amplified and phase-compensated by the servo unit 7, and the driving unit 6 drives the tracking coil 4b of the optical pickup. In order to follow the recording track stably even when vibration is applied from the outside, the phase margin and gain of the control system of the loop system such as the optical pickup mechanical system, optical system, electric system etc. It is necessary to secure enough room.

In the prior art, since the reproducing apparatus does not recognize the individual optical disc, the servo is automatically adjusted every time the optical disc is loaded. Also, the servo constants that have been automatically adjusted once are stored in a memory, and are read out from the memory and used as servo constants each time the power is turned on.

On the other hand, according to the present invention, according to the optical disk standard, an optical disk having a characteristic of a substantially central value of a required characteristic is set to a reference CD for servo adjustment (hereinafter referred to as a reference CD).
D) is stored in the storage unit, and data for recognizing the reference CD and data of the servo constant of the reference CD are stored in the storage unit 12 as a set of data. Further, the set of data has a data section that sets a flag when the first automatic adjustment is performed using the reference CD after the power is turned on. The flag is set to 0 when the automatic adjustment is not performed after the power is turned on, and set to 1 when the first automatic adjustment is performed after the power is turned on. This flag is cleared when the power is turned off or immediately after the power is turned on, and is set to 0. The control unit 8 includes the storage unit 1
By checking the flag of the data stored in No. 2, the loaded CD is the reference CD and the servo is automatically adjusted only at the first loading after the power is turned on.

The operation of the reproducing apparatus according to this embodiment will be described below. FIG. 3 is a flowchart showing the operation of the optical disk reproducing apparatus according to one embodiment of the present invention. Step S1
Is an operation of loading an optical disk into a reproducing apparatus. In steps S2 and S3, the servo constants before loading the optical disc are stored in the storage unit 12, and when the optical disc is loaded, the focus servo and tracking are performed using the data stored before loading the optical disc. T recorded on the optical disk with servo
Read the OC information.

In step S4, by reading the TOC information, disc-specific information such as the total playing time and the total number of tracks can be obtained as the unique information for identifying the optical disc. Is the reference C for servo adjustment registered in the storage unit in advance.
D can be determined. If the loaded optical disc is the reference CD registered in the storage unit in advance, the process proceeds to step S6. If the loaded optical disk is not a reference CD registered in the storage unit in advance, step S
The process proceeds to step 10, where the operation of reading the information on the recording track is started, and the sound is reproduced.

In step S6, it is determined whether or not the reference CD is the first loading after the power of the reproducing apparatus is turned on. If the reference CD is the first loading after the power of the reproducing apparatus is turned on, the operation of automatic servo adjustment is started. If the reference CD is the second or subsequent loading after the power of the reproducing apparatus is turned on, the operation proceeds to step S10 without performing the servo automatic adjustment operation, and the reproduction of the recording track is started.

Step S7 is a process for performing an automatic servo adjustment operation, and is the same as the means for obtaining gain and phase compensation data performed in the prior art.

In step S8, the data of the proper gain and phase compensation obtained by the automatic adjustment of the servo is updated as the data of the reference CD in the storage section, the automatic adjustment is terminated in step S9, and the reproduction of the recording track is performed in step S10. To start.

As described above, if the loaded disc is not the reference CD in step S4, step S5
The reproduction is started without performing the subsequent servo automatic adjustment operation. If the power is turned on for the second time or later in step S5, the reproduction of the recording track is started without performing the servo automatic adjustment operation in step S6 and thereafter. In this way, by automatically adjusting only the optical disk previously stored in the storage unit of the playback device, and automatically adjusting only when the playback device is turned on for the first time after the power is turned on, the conventional optical disk can be adjusted. Since the operation of performing the automatic adjustment every time the optical disc is loaded can be omitted, when loading an optical disc that has not been stored, the servo is immediately performed, and the audio can be output in a short time.

Also, a standard optical disk is periodically loaded with respect to the time-dependent changes of the laser diode, the four-segment detector, and the drive coil of the optical pickup.
If the servo constants are calibrated, the state of the proper servo constants can be maintained.

The reference CD described above can be registered by the user by designating an arbitrary optical disk in addition to the one designated by the manufacturer. When the user registers an arbitrary optical disk, the player presses a registration button (not shown) provided on the operation unit in FIG. Then, the servo is automatically adjusted, and the data of the servo constants obtained as a result of the automatic adjustment and the unique data for recognizing the optical disk are stored in the storage unit as a set of data.

In the above, an optical disk reproducing apparatus for a CD has been described as an embodiment of the present invention. However, as an optical disk, a DVD (Digital Versatile Disc), MD (Mini Disc),
A recording / reproducing apparatus using an LD (Laser Disk) or the like may be used.

The present invention is not limited to the optical disk, but may be a recording / reproducing apparatus having a recording medium for recording information and a recording / reproducing head for reading information, and performing appropriate control for recording / reproducing.

[0046]

According to the present invention, when an unregistered optical disk is loaded into the optical disk reproducing apparatus, the servo operation is not automatically adjusted, so that the servo is quickly applied and the recorded information on the optical disk is read and the sound is reproduced. Time can be shortened.

Even when the registered optical disk is reproduced, the servo automatic adjustment operation is performed only at the time of the first loading after the power is turned on, and the servo automatic adjustment is performed at the second loading after the power is turned on. Since the recording information on the optical disk is immediately read without performing the adjusting operation, the time until the sound is reproduced can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an optical disc reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a conventional optical disc reproducing apparatus.

FIG. 3 is a flowchart showing an operation of the optical disc reproducing apparatus according to one embodiment of the present invention.

FIG. 4 is a flowchart showing an operation of the optical disc reproducing apparatus according to one embodiment of the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk 2 Spindle motor 3 Optical pickup 4 Drive coil 4a Focuser drive coil 4b Tracking drive coil 5 Head amplifier unit 6 Drive unit 7 Servo unit 8 Control unit 9 Operation unit 10 Signal processing unit 11 DAC 12 Storage unit

Claims (5)

[Claims] 1. A recording / reproducing apparatus which controls a recording / reproducing unit to write or reproduce recording information on a recording medium,
Reproducing means for reading data recording unique information for identifying each recording medium from the recording medium, control means for controlling the servo characteristics of the servo system of the recording / reproducing unit to be appropriate, and identifying the recording medium Storage means for storing unique information, data of the servo characteristics of the recording medium as optical circuits and servo characteristics of the recording / reproducing section as a single loop servo system, and unique information for identifying the recording medium in the storage means; Operating means for instructing the recording medium to be reproduced, wherein the control means compares the unique information for identifying the recording medium to be reproduced with the information for identifying the recording medium stored in the storage means when reproducing the recording medium. And a recording / reproducing apparatus for controlling the servo characteristics to be appropriate when the information matches. 2. The recording / reproducing apparatus according to claim 1, wherein the control means, when reproducing the recording medium, information unique to the recording medium to be reproduced and information identifying the recording medium stored in the storage means. A recording / reproducing apparatus for storing, in the storage unit, servo characteristic data obtained by controlling the control characteristics to be appropriate when the information matches. 3. The recording / reproducing apparatus according to claim 1, wherein the control means, when reproducing the recording medium, information specific to the recording medium to be reproduced and information identifying the recording medium stored in the storage means. And if the information does not match, use the data of the servo characteristics that have been used continuously. 4. The recording / reproducing apparatus according to claim 1, wherein the control unit is configured to reproduce a recording medium when reproducing the recording medium.
The unique information for identifying the recording medium to be reproduced is compared with the information for discriminating the recording medium stored in the storage means, and when the information matches, the operation of controlling the servo characteristics to be appropriate is performed. A recording / reproducing apparatus, which is operated only once after the apparatus is turned on. 5. The recording / reproducing apparatus according to claim 1, wherein the control unit is configured to reproduce the recording medium when reproducing the recording medium.
The unique information for identifying the recording medium to be reproduced is compared with the information for identifying the recording medium stored in the storage means, and when the information matches, the information is output twice after the power of the recording / reproducing apparatus is turned on. A recording / reproducing apparatus characterized by using data of a servo characteristic which has been continuously used for a subsequent reproducing operation.